I think there's probably a pretty good argument for merging Wayne, Warren and Oakland counties in Michigan. It's quite striking that it wasn't until about 15 years ago that the Detroit metro (as opposed to Detroit itself) started to shrink and it's hard to avoid the conclusion that many of Detroit's problems are because 8 Mile Road meant the financial consequences of white flight were much worse than they'd have been if they stayed in the same county.
Possibly the solution would be something more like NYC or European metropolitan areas, where you have an overall city leadership and you then subdivide it into boroughs which have their own political leadership for more local priorities.
There's also a decent argument for altering the boundaries everywhere a city is in two or more counties and potentially for reshaping the map entirely and basing it around commuting patterns.
There is no Warren County in MI. Macomb?
Yes. An instance of brainfade.
